Answer :

In order to find the measure of angle AOC, let's start looking at point A.

Point A is in position 180, if we look in the upper numbers, and in position 0, if we look in the lower numbers.

Since it's easier to find the angle if one vertex is at position 0, let's consider position 0° for A.

Then, looking at point C, it is in position 130° in the upper numbers and 50° in the lower numbers.

Since we choose the lower numbers for A, we need to do the same for C.

Therefore A is in position 0° and C is in position 50°.

To find angle AOC, let's subtract both measurements/positions:

[tex]\text{AOC}=50\degree-0\degree=50\degree[/tex]

Therefore angle AOC measures 50°, and the correct option is C.